Automatic riveting assemblies, such as used in large-scale riveting operations for aircraft for example, typically include a rivet insertion assembly which utilizes fingers at the end of the insertion assembly to grasp a rivet, which is then inserted into a pre-drilled opening in a workpiece by a ram assembly acting on the rivet insertion assembly. Once the rivet is inserted, the ram assembly is used to upset the rivet, thereby completing a riveting cycle. Such automatic riveting machines typically operate with a rivet feed system in which rivets move from a storage hopper to the rivet insertion assembly fingers. In many arrangements, the feed system includes a ramp or a track which extends from the storage hopper to a position adjacent the rivet insertion assembly, at which point the rivet is injected into the insertion assembly fingers.
In vertical axis riveting, the workpiece is in a horizontal plane and the riveting is perpendicular to the workpiece. The rivet track or ramp is usually at a 30 degree angle ±10 degrees depending on style from the horizontal, so that the rivets slide down the track by gravity, which however results in an angular mismatch between the rivet track and the vertical fingers of the rivet insertion assembly. This mismatch results in jams and other compromises in operation of the riveting apparatus.